9
Installation
If the pitch angle is increased more air will be
displaced but higher power will be consumed,
and conversely, if the pitch is reduced less air
will be displaced and less power will be
consumed.
If tractor power is limited, then the pitch of the
fan blades should be reduced so that the power
absorbed by the fan in the high speed position
will leave sufficient power for the tractor to tow
the sprayer with full tanks at the required
operating speed over the prevailing ground
conditions.
To adjust the pitch, remove the mesh guard and
fan hub cover.
The cylindrical stub at the inner end of each fan
blade is located in a recess in the hub and is
clamped in place by a capping block attached by
two hexagonal head screws.
The blade angle can be altered by loosening the
balance screw either side of the hub and the
clamp screw that goes through the hub. The
blade can then be rotated. The pitch setting is
regulated by teeth moulded into the base of the
blade and a locking tab attached to the hub
clamp screw.
Each tooth on the blade is equivalent to 5
degrees of pitch angle. A reference line on the
blade is marked as 35 degrees of pitch and the
blade can be set between 20 and 45 degrees.
The standard pitch setting as delivered is 30
degrees.
Adjust one blade at a time and ensure that
each is set to the same pitch angle.
Check that the blade is positioned so that the
tooth on the locking tab engages the blade teeth
at the desired pitch setting.
Then securely tighten the
hub clamp screw
to
approx 20 N/M of torque (15 ft/lb).
The balance washer bolts can then be tightened
by just bringing the head of the bolt, or the
washer if fitted into contact with the hub clamp.
Do not tighten these any further
Do not remove the washers from the screws
attaching the clamping blocks as these are used
as weights to balance the fan. If the blades or
washers are removed or replaced the fan should
be rebalanced by your Silvan dealer.
Refit the hub cap and safety mesh after
adjusting the blade pitch.
See following page for fan blade
adjustment diagram.
Straightening Vanes
Non-adjustable stationary vanes are installed at
the rear of the fan cowling to improve the
alignment and uniformity of the airstream from
the fan.
The vanes impart a clockwise rotation to the
incoming air to counteract the directional bias in
the airstream which results from the anti-
clockwise rotation of the fan. With the vanes
installed the airstream will be more symmetrically
distributed about the centreline of the sprayer and
will provide more uniform crop coverage under
critical conditions.
Maximum operating pitch is 35
degrees. Any higher than this may
result in excessive clutch or
gearbox wear.
The tightening of the hub clamps is
very important. The bolts that hold the
balance washers must NOT have any
excessive torque applied when
tightening them. They should be just
done up to the point that the bolt head
or washer if fitted is just sitting
against the hub clamp and no tighter.
Please follow carefully the
instructions below.
